Undercutting device



J y 1930- E. J. DONCASTER 1,769,122

UNDERCUTIING DEVICE Filed May 28, 1928 INVENTOI? Mala 1000mm! Patented July 1, 1930 r 1 7 9 122.

UNITED STATES PATIENT." OFFICE f Application filed May 28, 1928.. Serial No. 280,998.

The invention is a device for holding saws 6 in which a pin 7 is slidably mounted and I 7 while cutting on the under side of timber the pin? isprovided with anotch 8 in which which may be driven into the log and readily aprojection 9 on the hub may extend which adjusted. will permit the pin 7 to slide and at the .5 The object of the invention is to provide I same time hold it in the hub.

a device for holding a saw while cutting on The arm 2 may be made as shown and pro,- the under side of timber or the like. 7 vided with a plurality of holes 10 to corre- Another object of the invention is to prospond with the opening 6 so that the pin7 vide a device for holding saws for cutting may extend into one of the holes 10 to hold 10 the under side of timber in which the pothe arm 2- in relation to he prong. The arm 6 sition of the saw in relation to the timber 2 is pivotally mounted upon the pin 11 in the may readily be adjusted. center of the prong and on the outer side of A further object of the invention is to the arm is a washer 12in which the outer end provide an under cutting devicehaving adof the pin 11 is riveted as shown in Figure 4. H 15 justing means in which the adjusting means It is understood however that the arm 2 may 65 is imbedded Within the body of the device be attached to the prong in any other suitand not provided with springs or the like. able manner. In the outer end of the arm 2 And a still further object of the invention is a pin 13 upon which the grooved roller is to provide a device for holding saws for 3 is rotatably mounted and in the outer end cutting timber which is durable and of a of the pin 13 is a pin 14 to hold the roller 7 simple and economical construction. upon thepin. The roller 3 may be of any With these ends in view the invention emother suitable design and may be mounted bodies a prong having a sharpened edge that in any other suitable manner. is adaptable to be driven into a log, a hub It will'be understood that changes may be on the prong, an arm pivotally attached to made in the construction without departing 75 the hub, means in the hub for holding the from the spirit of the invention. One of arm in various positions, and a grooved which changes may be in the design of the roller rotatably mounted on the outer end prong, another may be in the use of other of the arm. I I means for attaching the arm to the prong, and Other features and advantages of the instill another may be in the use of other. means 80. vention will appear from the following defor adjustably supporting the arm'upon the V scription taken in connection with the drawlog. I I

ings wherein: The construction will be readily under- Figure 1 is a view showing the device as stoodfrom the foregoing description. To use it would appear in use. the device the prong may be driven into a log 85v Figure 2 is a side elevation. of the device. as shown in Figure 1 and by withdrawing Figure 3 is an edge view of thedevice. the locking pin the. arm 2 may be set at such Figure 4 is a cross section on line 4=-4 an angle that the roller 3 will hold the sawof Figure 3. I against the under side of the log and it will 40 In the drawings the device is shown as be observed that as the saw cuts into the log 90 it would be made wherein numeral 1 indithe position of the roller may readily be adcates the prong, numeral 2 the" arm and justed by withdrawingthe pin and moving numeral 3 the grooved roller. the arm about. the point at which it is at- The prong 1 may be of any suitable detached to the prong. It will therefore be 0b sign and the arm 2 attached to it in any suitserved that this device provides a very efii- 95 able manner. In the design shown the outer cient means for holding a saw while underend of the prong is providedwith asharpcutting allog, makes it possibleto adjust the ened edge 4 and a hub 5 is rigidly mounted position of the saw as it cuts into the logand upon the prong as shown in Figures 2 and at the same time is of a very simple and du- 3. The hub 5 is provided with an opening rable construction. I I 1 Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent, is

In a device of the class described, a bar having a sharpened end, a hub on the said bar,

an arm pivotally attached to the hub, a plurality of openings in the arm arranged in a circle about the said pivot point, a'pin slidable in the said hub, said pin having a recess and said hub having a projection extending into the said recess, said pin'being adaptable toengagethe openings in the said arm to hold the arm in relation to the bar, and rotatable means at the outer end of the arin for sup 7 porting a saW.

v ENSLEY J. DONOASTER. 

